Yesterday I got my hair done in a salon. It was very light brown and was starting to look red, so I wanted to go back to my natural color (dark brown). I don't know what happened, we must have left the dye on for too long because my hair is now black and it looks terrible on me. I don't want to damage my hair too badly but I really want to redye it with the box color I got at the drugstore today. HELP!